BACKGROUND We examined the association of atrial fibrillation (AF) and oral anticoagulant use with perioperative death and bleeding among patients undergoing major noncardiac surgery. METHODS AND RESULTS A population-based study of patients aged 66 years and older who underwent elective (n=87 257) or urgent (n=35 930) noncardiac surgery in Ontario, Canada (April 2012 to March 2015) was perfor...